Chuck.



B. COCK.

annex.

APPLICATION TILED APR.9,1912. 1,121,550, Patented De0.15,1914.

Inventor:

Atty

ii I I( m 52 :5 :-T-'r 1 4 T g A a i can be inserted with greater I after UNIT STATES PATENT orrro. 1

BENJAMIN ooozgor CAMBORNE, ENGLAND, AssIenoa To HoL vrAN BROTHERS, LIMITED, 01 CAMBORNE, ENGLAND, A CORPORATION or GREAT BRITAIN.

and of the type in which the tool is'intro-j duced and held between a gripping-pad or bushing fitting into a longitudinal channel formed in the piston-head and a grippingwedge suitably secured to the piston-head, by a U-bolt or strap; and it has for its object to provide a chuck which is more simple and durable and in which the tool facility than heretofore. I

To this end the invention consists in certain novel features of construction, arrange ment, and combination of parts, as hereindescribed and" more particularly pointed out in the claim.

The invention is illustrated in the accompanying drawing, in which- Figure 1 is a side elevation of my im-' proved chuck, with part of the side wall of the head broken away; Fig. 2, a plan of the same; and Fig. 3, a section on the line 3 3 of Fig. 2.

The piston-head 5 is provided with a longitudinal channel or recess 6 which has a cylindrical, or otherwise suitably curved,

bottom and side walls and is open along the upper side and at the outer end of the head.

The longitudinally channeled gripping-pad or bushing 7 .has an outer surface conforming to the inner walls of the channel in the piston-head and its sides extend upwardly above the center of the channel and have transverse grooves 8 on each side midway of their length. The gripping-wedge 9, having the usual projections at its ends, fits within the open side of the channel in the head and the open side of the grippingad. ilie gripping-wedge between the projections on its ends and is secured to the pistonhead by the bolts 11' which pass down through holes 12in the head on each side of and opening into the channel therein The yoke 10 fits across the back of" Specificationof Letters Patents Patented Dec. 15,, 1914. Application filed April 9, 1912'. ,Serial No. 689,658.

and through the grooves in the sides .of the gripping-pad, thereby holding the pad in place'within the head, and are secured at the back of the head by the nuts 13.

The gripping-wedge is drawn back to permlt the insertion of the shank of a drill in the longitudinal channel provided there-- for in the gripping-pad andthen is driven forward to press the shank of the drill against the bottom of the channel in the gripping-pad, and, when in operation, its

momentum tends toforce the grippingwedge farther along thereby holding the drill more tightly in position.

It is evident that, whatever the, position of the piston-head, the gripping-pad or bushing cannot become detached or dis placed, being secured against lateral movement by the bearing of the walls of the channel in the head against its more than half cylindrical outer walls and against longitudinal movement by the bolts which engage the grooves in its sides, but is always held in position for the ready insertion of the drill, thus facilitating that operation. Moreover, if the yoke or either of the bolts is broken the broken part can be replaced by another, whereas the entire U-bolt heretofore used toseoure the gripping-wedge and the gripping-pad tothe head had to be repaired orreplaced in case of a break.

While I have shown and described my invention in what I now consider to be the best form of its embodiment it will be understood that it may be variously modified in its details, within the scope of the appended claim, without departing from the spirit or sacrificing the advantages thereof.

What I claim as new, and desire to secure by Letters Patent, is-

A chuck or tool-holder comprising a head which is longitudinally recessed along its upper side to form a more than half cylindrical axial channel therein, a cylindrical gripping-pad which is longitudinally recessed along its upper side to receive the shank of a drill and which fits and sub stantially fills the channel in the head and has transverse grooves formed in each of upper open sides of the head and grippingpad and which has its upper surface for- ,wardly inclined and terminated at each end in in registry With the transverse grooves in an upward proj ectionZ1 and a yokefwhicl in the outer. side Walls of the gripping-pad. bears against the tapere upper, sur ace 0 the gripping-Wedge and which is secured to BENJAMIN COOK 5 the head by independent bolts passing Witnesses:

through holes formed in the head on either W. J. HOBBINS, side of and opening into the channel there-V H H W F. K. BAKER.

Copies of this batent maybe obtained for five cents each, by addressing the Commissioner of Patents,

Washington, D. O. 

